Lifting jack



H. B. IMES.

LIFTING JACK.

APPLICATION FILED IUNEZB. mo.

Patented Mar. 14, 1922.

2 $HEETS-SHEET 1.

66% W J\ au-w SHEET 2.

Patented Mar. 14, 1922.

.2 SHEET 0 {7705711597 w V I PATiENT OFFICE.

1m! 1 or CHICAGO, mmois.

W8 JACK.

lpecijnltion of Letters Patent. Patented luar; 14, 1922? Applicationflail June" 28, 1920. Serial F0. 392,191.

To all whom it may concern:

Be it known that I, I'IARHY B. IMEs, a. citizen of the United States,cage, in the county of Cook and State of Illinois, have invented certainnew anduseful Improvements in Lifting Jacks, ofwhich the following is adescription.

My invention belongs to that general class of devices known as liftingjacks, and has for its object the production of such a device that willhe etiectiveand reliable in its operation, and which will improve andincrease advantages over devices of this'character heretofore available.

In the drawings, wherein like reference characters indicate like orcorresponding parts,

Figure 1 is a side elevation of the preferred form of my device; v

Figure 2 is a top plan view of the same;

Figure 3 is a vertical sectional view on line 33 of Figure 2-;

Figure 4 is a vertical sectional view on line 44 of Figure 1, showingthe jack ex tended to substantially ment.

Figure 5 is a top plan view of a rotatable sleeve supportedupon thestandard;

Figure 6 is an edge view of the same showing a part of the cooperatingthreaded sleeve; and

Figure 7 is a cross sectional view suhstantially on line 7--7 of Figure6.

In the drawings showing the preferred embodiment of my device, 1represents a. supporting column provided with a suitable base 2 andformed with a cylindrical opening extending longitudinally therein as at3.

A collar 4 formed to he loosely positioned within the cylindricalopening 3, carries upon its upper end a transversely extending heveledgear mernherlfi, which is adapted to rest upon the upper and ot' thebase I in such manner as to he freely rotated thereon. As shown inFigure 4, hall hearing 3 or equivalent friction reducing rrwmhers may heinterposed between tlumember ,3 and the upper end of the standard. 'ilu'ollar 4 1S internallv stretwthruadcd. as indi ated in Figures 4 and 0,for a purposiwhich will he hereafter described.

A bracket 7 is carried by the standard I, provided with a shaft 8extending from the bracket to the hod v of the standard, ,upon whichmounted the cooperating beveled residing at Uh i its limit of movegear 9arranged to engage the gear 5. Any preferred means may the gear 9 to bereadily rotated so as to rotate the gear 5 and its collar 4. As shown,the gear 9 has formed integrally therewith a cogwheel 10, forming aratchet to cooperate with asuitable pawl carried hy an-opcrating lever.11 is a pawl lever provided with an extension 12 loosely mounted on theshaft 8 and extended as at 13 to receive a suitable operatin r handle14. 15 is a spring pawl longitudina ly movable in an extension 16 andmaintaine in its operative position by a spring 17. The extension 16 inthe simple form shown has formed in its'upper edge a transverseslot 18,in which may be positioned a transverse pin 1!) carried on the springpawl. The paw-l has upon its upper enda head piece 20. By pulling thepawl outward, it will be freed from its engagement with the ratchet l0,and it may be rotated to bring its'rhisel point in the oppositedirection, whereupon the reciprocation of the handle will cause thecollar to rotate in the opposite direction. By this means the handle mayhe re'eiprocated to rotate the col lar 4 to secure the lifting effect,or when it -is desired to release the jack, by operating the pawl asdescrihed, lowering the lifting hat and tending to release the jack.

In the preferred form illustrateth the lifting bar is telescopicallvformed, providing a plurality of members arranged to engage one anotherto secure that effect. 21 is a sleeve screw-threaded on its exterior asat 22 to engage the-interior threads on the collar 4.; andscrew-threaded upon its interior as at 23 a suflir-ient distance toprovide secure engagement with the screw-threads 24 upon the exterior ofthe cooperating supplemental lifting har 25, the threads and 24extending in the same direction. The upper end of the supplemental ha!25 is provided with an engaging plate 211, or its equivalent. arrangedto contact with the hotly to he lifted.

lhe engaging plate 26 is removable from the har allowing the latter tohe placed in threaded engagement with 'the sleeve 21 from the bottom ofthe latter, the har 25 being provided with an enlarged section 27 orwith an equivalent arrangement so as to limit the upward movement of thebar and prevent its disengagement from the top of the sleeve '21. Thelifting sleeve 21 is likebe employed to enable wise-engaged with thecolla'r 5.- fronsi the bottom thereof. At the bottom it terminates in anextending shoulder 28, whichyasthe sleeve reaches its upward limit'ofimovement contacts with and engages ashoulder29 on the collar 4, thusstopping the rotation of the sleeve and preventing its accidental disupon engagement. A collar 30 is secured the upper end of. the sleeve 21in an mferred manner, and provided with '11 ex-' tending stop 31 which,as the sleeve reaches its lower limit of movement, engages with the stop32 carried upon the upper face of the member 5, thus limiting rotationin that direction. A cap piece 33 isadapted to be placed over the upperend of the telescopingparts, and is provided with a central open-*3 mgthrough which those parts may extend.

The cap dpiece is secured to the base in any preferre manner, forillustration, by means of bolts 34.

, Assuming that the tool is inthe osition shown in Fig. 3, thereciprocation o the lever 14 will rotate the integral pivotal gearandcollar to the right. caring in mind that the bar 25 is held HOD-POtatIVGby its engagement with the load to be lifted, or by other means, untilit is placed against said load, it is obvious that the rotation of the'ar 5 will also rotate the sleeve 21, because t ere is nothing to holdsaid sleeve from such rotation, and further, the friction between thesleeve and ar at the coo crating threads, which is in iiced by the lgad,increases the tendency of the gear and' sleeve to rotatras-one.

Therefore, the gear and sleeve act togather as a nut, considering thebar 25 as the bolt. It is a well known mechanical law that when a boltis held non-rotative and the nut is kept from sliding but is freelyrotatable, then any rotation of the nut causes the bolt to move axially.In the same nian ner the rotation of the gear and sleeve as anut causesthe bar 25 to be moved axially until the enlarged end 27 wedges againstor abuts the lower thread 23, limiting the in dependent movement of thesleeve and bar. Tlie'n'the sleeveill changes in its action from a nut toa bolt and forms in effect 'an extension of the bar 25, because althoughthe gear 5 still tends to rotate the sleeve 2l, such rotation would bein g, dlrection relatively downward of the lower end of the bar 25, and.as such movement is prevented by the enlargement 27, the sleeve canonly move axially with the bar 25. Therefore, the continued rotation ofthe gear 5 in the same direction causes the sleeve and bar to lift asone, as said gear is held against axial movement by the rap 33 and actsas a nut. This will continue until the. sleeve reaches tlie limit of itsmovement and the extension 38 engages with the shoulder '29, locking theparts together and preventing any further I goo net oignovement of thelifting elements of the a v P' g the pawl outward and turning-it oi ielialf rotation will bringit in the reverse engagement with the cog-rackor ratchet 10. The reciprocationv of the lever will thencause-thelreverse movement of the parts just described, and they willassume their original position.

35 is smiply'a'handle formed integrally with the standard for.convenience in handling the device,

Having thus described my invention, it is obvious that variousimmaterial modificatlgns may be made i the same without de- E gfrom' thespirit of my invention; eii ce;I'-' d,q%; not wish. to be, understood aslimlt'riigj'myself to the exact form, construction, arran'geinent andcombination of parts herein shown and described, or uses mentioned.

What I claim as new and desire to secure by Letters Patent is:

1. In a device of the kind described and in combination, a supportingbas'e formed with a vertically exten supplemental lifting bar, and asupplemental liftin bar externally threaded to engage said 5 eeve.

2. In a device of the kind described and in combination, a supportinbase formed with a vertically extending cy Indrical opening in thecenter, an internally threaded collar to tatably supported upon theupper end of the base, means for rotating said collar, a cooperatingsleeve externally threaded to engage with the thread in the collar andinternally threaded to engage .a telescoping sup lemental lifting bar,and a supplemental ift- "ing bar. externally threaded to engage saidsleeve, and means for reversing the rotation of the collar to restorethe parts to their normal position.

3. In a device of the kind described and in combination, a su portingbase formed with a vei'tically extending cylindrical opening in thecenter, an internally threaded collar rolatably supported upon the upperend of the base, an operating lever, a ratchet and pawl connectionbetween the lever and the collar, means for reversing the: operation ofthe ratchet and pawl connec ion, a cooperating sleeve externallythreaded to engage with the thread in the collar and internally threadedto engage a telescoping supplemental bar, and a supplemental lifting barexternally threaded to engage said sleeve.

4, In a device of the kind described and in combination, a supportingbase formed with a vertically extending cylindrical opening in thecenter, an internally threaded collar rotatably supported upon the upperend of the 1 base and provided at its margin with a beveled gear, acooperating beveled gear supported upon the device, arranged to engagewith the gear on the collar, an operating lever arranged to engage thecooperating hercled gear, a cooperating sleeve externally threaded toengage with the thread in the collar and internally threaded to engage atelescoping sup lemental lifting bar, and a supplemental li ting barexternally threaded to engage said sleeve.

5. In a device of the kind described and in combinatiolnm supportingbase formed with a vertically extending cylindrical opening in thecenter, an internally threaded collar rotatably supported upon the upperend of the base and provided at its eircpmfcrence with a beveled gear, acooperating gear member supported upon the device and arranged to engagethe beveled gear on the collar, said cooperating member provided with aratchet i device, an operating lever provided with a ,springpmvlarranged to engage the ratchet to rotate the same in either direction atiii,

a cooperating sleeve externally threaded 1e engage with the thread inthe collar and i ternally threaded to engage a telescopi! a supplementallifting her externally threaded to engage with said sleeve.

In testimony whereof, I have herenr fi signed my name in the presence oftwo sub scribing witnesses.

HARRY B. IMES Witnesses:

JOHN W. HILL, BERTIIA HARTMANN.

